A metaphosphate ion is an oxyanion that has the formula PO3−, the structure of which can be described as being made up of PO4 structural units in which each unit shares two corners with another unit. Cyclo-tetrametaphosphate compounds can have a wide range of applications including use as pigments, catalysts, food additives, and fluorescent materials. Different methods can be used to prepare cyclo-tetrametaphosphate compounds.